Rotary tool holding fixture



April 11, 1939. s. R. SCOTT ROTARY TOOL HOLDING F IXTURE Filed April 29,1936 2 Sheets-Sheet 1 .E. INVENTOR. G'eorje R 5601?.

BY r

ATTORNEY6.

April 11, 1939 e. R. SCOTT ROTARYiTOOL HOLDING FIXTUREv Filed April 29,1936 2 Sheets-Sheet 2 INVENTOR. Geo 2:46 R 5601?? B Y I I 1 A TTORNE Y5.

Patented A m 11,1939

UNITED STATES PATENT OFFICE.

no'rsnr 'roor. .nomme FIXTURE George R. Scott, Detroit, Mich.

Application April 29,

' 6 Claims.

This inventionrelates to a rotary tool holding fixture primarilydesigned for holding tools utilized for machining globoidal type worms.

In order to maintain a more complete understanding of the presentinvention, reference may be had to applicant's copending application,Serial No. 572,527, filed November 2, 1931, relating to a tool holdingfixture utilized for substantially the same purposeas the tool holdingfixture of the 10 present invention. The present application is acontinuation in part of applicants abovementioned prior co-pendingapplication insofar-Ts the features of the invention are common to bo hcases.

It has been found essential in apparatus for machining worms of thistype that the cutting edge of the tool be maintained at all times in api'ane tangential to a predetermined base circle. It is also essentialthat the cutting edge of the tool lie in a horizontal plane passingthrough the axis of rotation, of the worm being machined. It

is therefore essential that simple and accurate means he provided forthe adjustment of the tool" in the fixture in which it is mounted inorder that the cutting edge may be positioned accurately upon thispredetermined line. Further, it will be appreciated that the cuttingedge of the tool will be displaced substantially, every time the 'toolis sharpened and accurate adjustment is therefore necessary to readjustthe tool to predetermined position after sharpening.

It is an object of the present invention to provide means for mounting acutting tool for machining globoidal worms, which'means'not onlyincludes simple and effective apparatus for positioning the cutting edgeof the tool in a predetermined line, but which also permits of accurateangular adjustment of the tool in order to regulate the amount of reliefbetween the cutting 40 tool and the tooth surface being machined.

It has long been appreciated that the angle of relief between one faceof the tool and the tooth surface which it engages is a critical factorin determining the efliciency of the cutting obtained.

In order to provide a tool holding fixture which may satisfactorily beused for machining various worms of different pitches, it is virtuallyessential that some simple and efiective'meansbe provided for adjustingthe angle of the tool with respect to the tooth fac'eagainst which thecutting edge is disposed.

The present application contemplates the provision of a tool holdingfixture which has a plurality of turrets mounted thereon. These turretsare each individually positioned in order that they 1936, Serial a...76.944

may beadjusted so that the tool held in the turret is positionedtangential to a predetermined desired base circle. The turrets eachinclude a tool holding element rotatably'. mounted therein on an axisparallel to the cutting edge of the tool 5 in order that simple andeffective means may be provided for adjusting the angle of relief of thetool with respect to the tooth surface which it engages. The toolholding element within the turret includes means for positioning thetool in 10 order that the' cutting edge thereof will lie in a planepassing through the axis of rotation of the work.

Many other and further objects and advantages of the invention willbecome clearly apparent from 18 the following specification whenconsidered in connection with the accompanying drawings forming a partthereof;

In the drawings:

Figure 1 is a fragmentary plan view diagram- 20 matically illustrating aportionof the improved tool holding fixture, showing one turret thereofand the manner in which the turret is mounted on the fixture;

Fig. 2 is a vertical sectional view, with parts 25 in elevation, takensubstantially along the line 2-2 of Fig. 1, illustrating the manner inwhich the tool is mounted and the mechanism for adjusting the verticalposition thereof;

Fig. 3 is an elevational view of the turret, illus- 30 trating themechanism for varying the relief angle of the cutting tool;

Fig. 4 isa plan view of a modified form of the invention, showing a toolholding fixture having a plurality of tool holding turrets thereon; and

Fig. 5 is an elevational view of one of the tur-. rets, illustrating themanner in which an. individual tool is mounted thereon.

With more particular reference to the drawings, the specific embodimentof the invention dis- 40 closed includes a rotarytool supporting tablel0 having a plurality of radially disposed slots H' therein. The slots Hare preferably sufliciently undercut to receive the heads of bolts 62and it is preferable to form the slots ll of such cross 45 sectionalconfiguration that the bolts I2 may be moved radially therealong andpositioned any desired distance from the axis of rotation of therotarysupport In. The bolts I! are each .pro-" vided with nuts l3 whichserve to-engage the 50 upper surface of clamps I! through which thebolts l2 passand, as is clearly seen in Figs. 1 and 3, these clampsserve to accurately position a removably mounted turret 15 uponthewupper sur-, face of the rotary work table l0.

As is conventional in constructions of this general character, therotary table it is driven from a suitable source of power and by meansof mechanism conventional inthe art, a roughed-out worm blank I6 issynchronously driven with respect to the rotary table, the relativerotation of these two members being controlled in strict accordance withthe ratio between the worm to be cut and the worm wheel with which theworm is intended to mesh.

The turret l5 has a cylindrical transverse bore I 8 extendingtherethrough, and the turret is preferably so positioned that the axisthereof lies in a plane which will pass horizontally through the axis ofrotation of the worm IE to be machined. A cylindrical tool holdingmember I9 fits snugly within the bore I8 and is provided with an axiallyextending slot "of sufficient width to receive a cutting tool 2!. Theslot is preferably so formed that one wall'thereof lies in a diametralplane passing through the axis of the tool holding member l9 andtheupper wall of the slot preferably also lies in a diametral planeintersecting the side wall at right angles at the axis of the toolholding member iii. A pair of cooperating wedges 23 and 26 are disposedin the slot beneath the tool 2| and the wedge 24 preferably has threadedtherein a locking screw 25 which. as will be seen by reference to Fig.2, when tightened, will serve to firmly position the tool in the slot 20with the cutting edge thereof lying exactly in the axis of thecylindrical tool holding'member l9. 7

. It will be apparent that the tool holding member I9, due to itscylindrical configuration, may be adjusted angularly in the bore l8 andmay be locked in positionby means of a pair of locking screws 21threaded through the wall of the turret l5 and each-providedwithsuitable lock nuts As is conventional in constructions of this kind.when the tool 2| is sharpened, the entire upper surface thereof isground away in order that the cutting edge will lie in the upper surfaceof the tool. Consequently, after the tool has been sharpened, it may bepositioned in the slot 26 and the cutting edge thereof will at all timeslie in the axis of the cylindrical tool holding member i9 irrespectiveof the amount of the tool which has been ground away as the result ofrepeated sharpening operations. The tool contemplated by the presentapplication is utilired for the purpose of finishing only one side ofthe tooth structure of the worm and it will be clearly seen by referenceto Fig. 1 that the tool holding 'member is may be rotated to a positionso that the relief angle at which the tool engages the surface of thetooth to be cut may be adjusted, as may be desired, to obtain maximumefliciency irrespective of the pitch of the worm being operated upon.

In the apparatus shown in Figs. 1, 2, and s of the drawingadt will bereadily appreciated thatafter the cutting tool 2| has been positionedand used for the purpose of machining one side of the tooth structure ofthe worm IS, the tool holding member I! may be rotated to' the desiredposition and the same tool may be utilized for machining the oppositesurface of the tooth, and it will be seen that the desired relief anglemay be obtained at all times.

In the modified form of the invention shown I in Figs. 4 and 5, a toolholding fixture is disclosed which embodies substantially the samegeneral teachings disclosed in Figs. 1 to 3, inclusive. This apparatusincludes a rotary table 30 having a plurality of turrets 3i boltedpermanently in position thereon by means of suitable verticallyextending bolts 32. Each of the turrets has a cylindrical bore 33extending horizontally therethrough and the turrets are preferably sopositioned that the axis of this bore lies tangential to thepredetermined desired base circle and at the same time lies in ahorizontal plane passing through the axis of the work to be machined.The turrets each include a cylindrical tool holding member 35 snuglyfitted within the bore 33 and retained in predeterminedangular positionby means of suitable set screws 36. The rotary tool holding member 39has a tool receiving slot 31 therein, one of the sidewalls of which liesin a plane passing through the axis of the tool holding member andintersecting the top wall of the slot at right angles at this axis.Suitable cutting tools 38 are retained in position in each of the slotsby means of cooperating wedges 3s and 40 substantially identical inconstruction and operation as the wedges 23 and 24 described inconnection with the embodiment of the invention shown in Figs. 1 to 3.

It will be appreciated that in this modified form of the invention theturrets may be adjusted in position so that one pair of the tools willserve to machine one side of the tooth structure of the worm and theother pair of tools will serve to machine the opposite side of the toothstructure. In each instance it willbe appreciated that the tool holdingmember 35 may be adjusted to a position in ,ord.er that the relief angleof the cutting edge of the tool will be positioned at an angle ofmaximum emciency with respect to the tooth surface which it engagesirrespective of the pitch of the particular worm being machined. Thisaccurate adjustment is obtained by the rotation of the tool holdingmembers in their respective turrets. The turrets 3| are so positionedupon the rotary wori: table 30 that the tools will occupy substantiallythe position of individual teeth upon a worm wheel with which the wormis subsequently adapted to mesh. This modified form of theinventionmakes possible the relatively rapid machining of a worm being treatedand makes possible the machining of both sides of the tooth structurethereof in a single operation.

It will be appreciated that the above described embodiments of theinvention are merely illustrative of the generic inventive conceptpresented and that many other and further modifications falling withinthe scope thereof and defined in the subjoined claims will be apparentto those skilled in the art. Y

I claim as my invention:

1. A tool holding fixture for machining tooth surfaces on aworm of thegloboidal type, comprising a rotary table, a turret mounted on saidtable, a tool holding element mounted in said turret and adapted foradjustable rotation about an axis tangential to a predetermined basecircle; and means for locking 9. tool in said tool holding member withthe cutting edge of said tool lying in the axis thereof.

2. In a rotary tool holding fixture for machining globoidal worms, arotary table, a turret adjustably mounted upon said table whereby a toolin said turret may be adjusted to a position in which the cutting edgethereof is tangential to a 7 tool and the surface of a y s. A toolholding fixture comprising 9,

mybeadi i a 3. Apparatus for nnishins sears comprising a tool holdingmember of generally cylindrical com figuration, a cutting tool lockedin'position in said member, said cutting tool having-a out edge lying inthe axis of said tool holding member, and means for adiustabiy mountingsaidtool holding member for rotation about its 4. Apparatus forfinishing globoidal we comprising a supporting turret having acylindrical bore ing member rotatable in said bore, me for locking saidtool holding member ag' rotation, a cutting tool carried by d tool hoimember, said cutting too! having s,

rotation of said tool hoi bet the predetermined position 03 the cuttially cylindricaltool no! gn -glitch?! eseae'ee therethrough. acylindrical to'oi hold- '2 cut- 7 ting edge lying in the or said borehere y.

slot therein, we slot having a bottom and a side wall, said bottomwailand 'side wall inter secting inthe axis of saidtool holdim; member;

' a cutting tool having a shank inclu intersection surfacescomplementalto said bottom and said walls of said slot, said cuttingtool having a cutting edge lying in the line of intersection of saidsurfaces whereby when said tool is seated in said slot the cutting edgethereof willbe in the axis oi saidtooi holding member,

for machining tooth 6; A tool holding fixture gioboidal type,comsurfaces of a worm of the i prising a rotary table, a turret mountedon said table, said turret having a cylindrical bore there-

